1. Field of the Invention
The present invention relates to an information processing apparatus and, in particular, to an information processing apparatus allowing the streaming transfer of audio data in realtime.
2. Related Art
A wireless communication technology especially among communication technologies is being in the limelight recently. With a wireless communication technology, the establishment of communication between/among electronic equipment and terminals in a wireless scheme can simplify connection works between/among the electronic equipment and terminals and eliminate the limitation of the places where the electronic equipment and terminals are to be placed. Therefore, the use of a wireless communication technology provides higher convenience than the use of a wired communication technology.
For example, the use of a wireless LAN allows the easy construction of a network such as a home network locally and even in a place where the construction of a network cable is not realistic.
The Bluetooth™, for example, has been known as a wireless communication technology applicable to electronic equipment. The use of the Bluetooth as a wireless communication technology may allow the transmission of audio data (music data) from an audio player containing a CD player to a speaker, for example, without via an audio cable.
Furthermore, the transfer of audio data from a mobile information terminal or mobile music player of a cellular phone, for example, to a music player such as a headset may be allowed thereby without via an audio cable.
The technical specifications of the Bluetooth may be divided into Core and Profile. The Core defines the base of wireless connection provided by the Bluetooth. On the other hand, the Profile is a set of technical requirements defined for each function for guaranteeing the mutual connectivity between equipment when functions and/or applications developed based on the Core of the Bluetooth is/are built in the equipment.
The Bluetooth has multiple Profiles and provides one application including a combination of the Profiles. Actually, a combination of profiles providing an application may be implemented in a product along with the Core.
Various Bluetooth Profiles may be assumed such as profiles relating to a cellular phone, a personal computer, a vehicle, a network and a printer and audio and video Profiles.
As a profile for the transmission of audio data, “Advanced Audio Distribution Profile” (Advanced Audio/Video Distribution Profile (Bluetooth SIG)) and “Generic Advanced Audio/Video Distribution Profile” (Generic Advanced Audio/Video Distribution Profile (Bluetooth SIG)) have been known, for example. These are specifications for performing the streaming transfer of audio data in realtime between/among Bluetooth-connected equipment.
In a mobile information terminal or mobile music player of a cellular phone, for example, audio data may be compressed by SBC, MP3, or ATRAC3, for example, and be transferred in packets. On the other hand, a music player such as a speaker and a headset simultaneously receives and plays data without waiting until the receipt of all packets. Thus, a user can hear the sound from a mobile information terminal or a mobile music player through a music player such as a speaker and a headset.
However, though the specifications proposed in Non-patent Documents 1 and 2 do not assume a case where functions excluding audio data playing and transferring functions are performed simultaneously in order to perform realtime streaming transfer of audio data by using a mobile information terminal, which is one of information processing apparatus having a music playing function though the specifications define the procedure for realtime streaming transfer of audio data. Thus, when the implementation of the other functions than the play and transfer of audio data imposes a high load on the CPU in the mobile information terminal, the underflow of the audio data to be transferred occurs, which causes the intermittent grating interruption of sound.